pl.wavesoftware.eid.exceptions.Eid Maven / Gradle / Ivy
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/*
* Copyright 2015 Krzysztof Suszyński .
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package pl.wavesoftware.eid.exceptions;
import javax.annotation.Nullable;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import static java.lang.Math.abs;
/**
* This class shouldn't be used in any public API or library. It is designed to be used for in-house development
* of end user applications which will report Bugs in standardized error pages or post them to issue tracker.
*
* Exception identifier for all Eid Runtime Exceptions.
*
* @author Krzysztof Suszynski
*/
public class Eid implements Serializable {
public static final String DEFAULT_FORMAT = "[%s]<%s>";
public static final String DEFAULT_REF_FORMAT = "[%s|%s]<%s>";
public static final String DEFAULT_MESSAGE_FORMAT = "%s => %s";
public static final UniqIdGenerator DEFAULT_UNIQ_ID_GENERATOR = new StdUniqIdGenerator();
private static final long serialVersionUID = -9876432123423401L;
private static final int FORMAT_NUM_SPEC = 2;
private static final int REF_FORMAT_NUM_SPEC = 3;
private static final int MESSAGE_FORMAT_NUM_SPEC = 2;
private static final String EMPTY_REF = "";
private static String messageFormat = DEFAULT_MESSAGE_FORMAT;
private static UniqIdGenerator uniqIdGenerator = DEFAULT_UNIQ_ID_GENERATOR;
private static String format = DEFAULT_FORMAT;
private static String refFormat = DEFAULT_REF_FORMAT;
private final String id;
private final String ref;
private String uniqueId;
/**
* Constructor
*
* @param id the exception id, must be unique developer inserted string, from date
* @param ref an optional reference
*/
public Eid(String id, @Nullable String ref) {
this.id = id;
this.ref = ref == null ? EMPTY_REF : ref;
}
/**
* Constructor
*
* @param id the exception id, must be unique developer inserted string, from date
*/
public Eid(String id) {
this.id = id;
this.ref = EMPTY_REF;
}
/**
* Sets a format that will be used for all Eid exceptions when printing a detail message.
*
* Format must be non-null and contain two format specifiers "%s"
*
* @param format a format that will be used, must be non-null and contain two format specifiers "%s"
* @return previously used format
* @throws IllegalArgumentException if given format hasn't got two format specifiers "%s", or if given format was
* null
*/
public static String setMessageFormat(String format) {
validateFormat(format, MESSAGE_FORMAT_NUM_SPEC);
String oldFormat = Eid.messageFormat;
Eid.messageFormat = format;
return oldFormat;
}
/**
* Gets actually set message format
*
* @return actually set message format
*/
public static String getMessageFormat() {
return messageFormat;
}
/**
* Sets the actual unique ID generator that will be used to generate IDs for all Eid objects. It will return previously used
* generator.
*
* @param uniqIdGenerator new instance of unique ID generator
* @return a previously used unique ID generator
* @throws IllegalArgumentException if given generator was null
*/
public static UniqIdGenerator setUniqIdGenerator(UniqIdGenerator uniqIdGenerator) {
if (uniqIdGenerator == null) {
throw new IllegalArgumentException("Unique ID generator can't be null, but given one");
}
UniqIdGenerator previous = Eid.uniqIdGenerator;
Eid.uniqIdGenerator = uniqIdGenerator;
return previous;
}
/**
* Sets the actual format that will be used in {@link #toString()} method. It will return previously used format.
*
* @param format a format compliant with {@link String#format(String, Object...)} with 2 object arguments
* @return a previously used format
* @throws IllegalArgumentException if given format hasn't got two format specifiers "%s", or if given format was
* null
*/
public static String setFormat(String format) {
validateFormat(format, FORMAT_NUM_SPEC);
String previously = Eid.format;
Eid.format = format;
return previously;
}
/**
* Sets the actual format that will be used in {@link #toString()} method
*
* @param refFormat a format compliant with {@link String#format(String, Object...)} with 3 object arguments
* @return a previously used format
* @throws IllegalArgumentException if given format hasn't got tree format specifiers "%s", or if given format was
* null
*/
public static String setRefFormat(String refFormat) {
validateFormat(refFormat, REF_FORMAT_NUM_SPEC);
String previously = Eid.refFormat;
Eid.refFormat = refFormat;
return previously;
}
/**
* Makes a log message from this EID object
*
* This method is for convenience of usage of EID in logging. You can use it like this:
*
* log.debug(new Eid("20151025:202129").makeLogMessage("A request: %s", request));
*
* @param logMessageFormat a log message format as accepted by {@link String#format(String, Object...)}
* @param parameters a parameters for logMessageFormat to by passed to {@link String#format(String, Object...)}
* @return a formatted message
*/
public String makeLogMessage(String logMessageFormat, Object... parameters) {
String message = String.format(logMessageFormat, parameters);
return String.format(getMessageFormat(), this.toString(), message);
}
@Override
public String toString() {
if ("".equals(ref)) {
return String.format(format, id, getUniq());
}
return String.format(refFormat, id, ref, getUniq());
}
/**
* Getter for constant Exception ID
*
* @return ID of exception
*/
public String getId() {
return id;
}
/**
* Get custom ref passed to Exception ID
*
* @return ID of exception
*/
public String getRef() {
return ref;
}
/**
* Gets unique generated string for this instance of Eid
*
* @return a unique string
*/
public String getUniq() {
if (uniqueId == null) {
uniqueId = uniqIdGenerator.generateUniqId();
}
return uniqueId;
}
private static void validateFormat(String format, int numSpecifiers) {
if (format == null) {
throw new IllegalArgumentException("Format can't be null, but just received one");
}
List specifiers = new ArrayList();
for (int i = 0; i < numSpecifiers; i++) {
specifiers.add(i + "-test-id");
}
String formatted = String.format(format, specifiers.toArray());
for (String specifier : specifiers) {
if (!formatted.contains(specifier)) {
throw new IllegalArgumentException("Given format contains to little format specifiers, "
+ "expected " + numSpecifiers + " but given \"" + format + "\"");
}
}
}
/**
* It is used to generate unique ID for each EID object. It's mustn't be secure because it just indicate EID object while
* logging.
*/
public interface UniqIdGenerator {
/**
* Generates a unique string ID
*
* @return a generated unique ID
*/
String generateUniqId();
}
private static final class StdUniqIdGenerator implements UniqIdGenerator {
private static final int BASE36 = 36;
private final Random random;
private StdUniqIdGenerator() {
this.random = getUnsecuredFastRandom();
}
@Override
public String generateUniqId() {
long first = abs(random.nextLong() + 1);
int second = abs(random.nextInt(Integer.MAX_VALUE));
int calc = (int) (first + second);
return Integer.toString(abs(calc), BASE36);
}
private static Random getUnsecuredFastRandom() {
return new Random(System.currentTimeMillis());
}
}
}